Hardness testing machine



June 17, 1941. c. E. SMITH 2,246,146

HARDNESS TESTING MACHINE Filed Oct. 3, 1938 2 Sheets-Sheet 1 I Smaentor Qfl/PE/VCE 5'. 071/274.

June 1941- c. E. SMITH 2,

HARDNESS TESTING MACHINE J5 i 6 I if 4 m g i 6 T 2/ "keg k A v s E g A /4 7 A Z i 22 Snventor Q/WE/Vffl. 5/7/29.

Patented June 17, 1941 Clarenc a. smite, Dearborn, assignqr to Pyro-Electro'lns'tifilment cm, Detroit, Miehl, a

corporation" of Michigan Application October s, 1938; see-mo. 233,048

eelaimsz (or; 26 12) invention relates generally to hardness 4 testing: machines and more particularly to automatically operable hardness testing machines.

In-the past, hardness testing machines have been provided which have been eflicient' in giving L a substantially accurate indication of the hardpointwhere an average hardnessreading' onthe,

material maybe obtained; Usually, the minor loadis applied by-raisingthe material under test, on an adjustable supportagainst a penetrator until an indicator registers the desired minor load to be applied after which the major load I isapplied to the material. The application of these-called minor load on hand operated machines requires time, and the accuracy with which the load isapplied, particularly in viewof variations inthe gaugesoi materials to be tested;

d'ependssomewhat up'onthe skill of theoperator.

Accordingly, it is'an object of the present invention toprovide-a new and improved'hardness testing machine which is entirely automatic in operation-,requiring only manual: feeding of material tothe machine.

Another object of the invention'is' to provide a new and impr'ovedhardness testing ma'chine in whic'happlication of the minorload by an operator 'i's eliminated'.

Another objectof the-invention-isto provide a new and improvedhardnesstesting' machine which automatically compensates for variation in gauge l of materials-'- to be tested.

Other objects of the invention will become ap-' parent from the following description taken in connection with-the accompanying drawings, in Which Figure 1 is a view partly in elevation andpartly in'section of a hardness testing machine'embody-- ingmy invention;

Fig. 2'is an enlarged fragmentary view partly in elevation and partly in section of certain of the operating parts of themachi'ne;

Fig. 3 is a view shown partly in section taken along the line and'in the direction ofthe arrows 3'& of Fig. 2; v

Fig. 4 is aview in section of-a c1utch-part employed in the machine;

Fig. 5 isatop plan view of the partshown in'Fig. 4}

Fig. 6 is a fragmentary end view of the machine looking; from: right-to'left of Fig.2, and

Fig. '7 is a detail=view-- in side elevation taken in the direction of the arrow l -=1 ofsFig; 1.

Referring tothe drawings by characters" of reference, the present hardness testing machine includes-a casingl-0= having a lower compartment M andzu-pper compartment l2 separated:-by a horizontal wall t3 whichincludesan extended wallypdrtion I4 projecting over and vertically spaced froman extended base portion of the casing. Secured theextended base-1 portion 1 5; an open ended,- internally-threadedtubular member or fitting i6 is provided and-receives a vertically adjustable; externally threaded screw H-; which carries a supporting member He for supporting material, as at l8, to be tested: The

screw Ilmay be raised and/or loweredby any suitable means; suchas'for example by a-hand wheel ifl which 'maybe secured to the screw in any" suitable manner; The hand wheel being secured .to the screw I! and the internally threaded fitting I'B being secured to the base;-the screw" may beraisedand/or lowere'dby rotation of the hand wheel.-

Immediately overlying. the adjustable support I'huthe extended casing wa'll portion M-isprovided withanapertureor bore-2i therethrough which is closed at its=lower end by a/tubular open endedguide member 22 which slida-bly receives and guides avertically reciprocal supporting which a penetrator 24*, preferably a pointed-diapartment I 2*, a U-shaped-supporting block 25 -overliesatheopening 21 and through" one, orits 40 lower-leg, asat 26', iseprov'ided anaperture 21 to-"receive atubular'member 2-8 ,"thelower end of the tubular member 28- abutting the upper end-or the supporting rod- 2 3. In the upper leg, as at 30;. of the U-shaped block-- 2-5; avertical bore 3h is provided t herethrough and in its lower end a tubular insert provides adownwardly facing seat 32'for a ball 3-3-which serves as a fulcrum or. pivot for a" lever-or beam 3 4' which adjacent one endthereof is provided with-an'upward-ly faci'ngsocket to receive the ball 33*. The pivoted end ofthe lever 34 is preferably bifurcated to receive a' roller' 36 which rides-on the upper end or the tubular member 28" to reduce frictionbetweenthe-parts; the roller being mounted on the lever by a pivot pin 31'. Apair of helical coil springs 36a under tension is provided and acts to retain the ball pivot 33 on its seat. A pair of vertically extending guide members 31a of which only one is shown, Fig. 1, may be provided on opposite sides of the lever 34 to limit lateral or side movement thereof. The upper end of the tubular member 28 may have an external flange 38 to provide an enlarged abutment or bearing surface for the roller 36, but this flange 38 is interrupted, or is substantially semi-circular as shown in Fig. 3 so that the upper end as well as the lower end of the tubular member 28 is open. With this arrangement, the roller 36 is arranged clutch member 61 carried by the indicator operating lever 63. The clutch member 66 is in the form of a pin having a shank which fits into a i bore 68 in the upper end of the penetrator supto ride on the upper surface of the flange 38,.

offset from the vertical or longitudinal axis of the tubular member 28.

Pivoted to the lever 34, adjacent the end which is opposite the lever fulcrum, is a depending predetermined weight 46 which is operable to exert a force through the lever 34, and member 28, to

urge the penetrator 24 downwardly and penetrate the material I8 to test the hardness thereof. The casing wall I3 may be provided with a recess 4| to receive the Weight member 40. Integralwith and projecting upwardly from the wall l3=on the opposite side of the weight, from the penetrator is a pair of lugs 43, only one of which is shown and these lugs support a pivot pin 44 on which an oscillatory lever or rocker member 45 is pivoted to raise and lower the Weight member 46, In the present instance, the lever member 45 comprises two spaced, substantially parallel arms 46, only one of which is shown, and connecting the arms 46 is a pin 41 on which a reduced extended portion 48 of the lever 34 rides. Intermediatetheir ends, the lever arms 46 are integrally joined by a transversely extending abutment member 58 against the underside of which the rounded upper end of a vertically reciprocal push rod 5| abuts, the push rod 5| being actuated by a cam or eccentric 52 which is rotated through suitable speed reduction gears .in a casing 53, by an electric motor 54, located in the lower compartment ll. Lead wires 55, 56

lead to the electric motor 54 and a manually operable switch 61 may be provided in the line 56 to start and/or stop operation of the motor 54.

Mounted on the casing I0, externally thereof, is an indicator 66 for indicating the hardness of material in accordance with the operation of the penetrator and the indicator 60 may be of any tudinally of the tube 61, an operating lever 63 has its opposite ends projecting from the tube and is operatively connected to the indicator 6!), l the operating lever 63 being pivoted intermediate its ends on a pivot pin 64 having its opposite ends "secured in and to the side wall of the tube.

In order to provide a completely automatic hardness testing machine by means of which parts may be tested at a high rate of speed and one in which the application of the minor load is not dependent upon the skill of the operator, I provide a lost-motion connection or slip clutch for operatively connecting the indicator operating lever 63 and the penetrator 24, This clutch comprises a clutch member 66 carried by the penetr'ator supportin'g'member 23. and a cooperating port 23 and having a conical head 69 which is received in a chamfer in the upper end of the bore 68. The head 69 projects above the upper end of the penetrator support 23 and is rounded, the lower open end of the tubular member 28 seating on the rounded head of the clutch member. The clutch member 66 is provided with a bor 18 which opens through the rounded upper surface of the head 68 to receive the other clutch member 61 which may be in the form of a wire. The upper end of the wire or clutch member 61 is secured to the inner end of the indicator operating arm 63 and the wire depends therefrom extending through the tubular member 28 into the bore 18 of the other clutch member 66. The upper end portion of the clutch member 66 is provided with a plurality of slots 12 which open through the upper rounded surface of the head 69and intersect the central bore 10 which receives the wire clutch member, which slots provide for peripheral expansion and contraction of the upper end portion of the clutch member 66. When the clutch member 66 is expanded its bore 18 is slightly larger in diameter than the diameter .of the wire or clutch member 61 permitting relative movement of the clutch members, but upon predetermined pressure on the rounded head of the clutch member 61 by the weight 48 via the lever 34 and tubular member 28, the upperend portion of the clutch member 66 contracts peripherally, gripping the. wire clutch member 61 and establishing operative connection between the indicator 68 and the penetrator 24. A coil spring 13, Fig. 2, surrounds the penetrator support 23 within the guide 22 and acts to move the penetrator upwardly on upward movement of the weight 40 to its inactive or ineffective position.

A lower end portion of the tubular member 22 is reduced, as at 15, to receive an open ended sleeve 16 which is rigidly secured thereto, and the sleeve is internally threaded at its lower end .to receive a tubular guard and gauge 11 for the penetrator 24. The tubular guard 11 surrounds the penetrator 24 and is provided with a lower end wall 18.which conforms in shape to the lower conical or pointed end of the penetrator. The end wall 18 is frusto-conical having a downwardly facing, fiat seating surface for abutment with the upper surface of the material I8, the wall 18 being provided with an aperture for projection of the pointed end of the penetrator externally of the guard upon predetermined downward movement of the penetrator.

In order to compensate automatically for variations in thickness or gauge of a number of pieces of material tested, the Support 11a is vertically movable relative to the screw l1 in accordance with the operation of the machine. To this end, a cam mechanism 88 interposed between the screw 11 and the support He, is provided and is controlled by a control or tilt switch 8|, Fig. 1, which is actuated in accordance with the operation of the penetrator 24. The cam mechanism comprises a lower cam member 82 and an upper cam follower 83, the cam 82 being rigidly secured to the screw 11 and the follower 83 being integral of the support 11a. The cam 82 and the follower 83 are provided with extended annular flanges 84 and 85 respectively, on the ends'of which are provided complementary cam surfaces 85a. These cooperating cam surfaces -counterclockwise :direction facing Fig. 1.

switch 81 is pivoted, as'at I'D-I to a bracket 1'02 1 85a are 'provided witha plurality of spaced-risers "8-6, theangles-of which risers are thesame'and these riser surfaces 8% are only slightly inclined with respect-tofthe horizontal so that together with the largeconta'ct area of the cam and tollower surfaces, frictional resistance is provided which will resist and prevent rotation and downward movementof the support 11 a 'by and upon app'lication'of the force or weight 411. Surrounding the cam 82 and follower 83, a sleeve-884s provided which is secured to the cam folio'wer 83 for rritation therewith land cooperates with the cam 82- to-"guid'e the follower. A i

- Rrigidlyisecured tozthe screw --l l-, a lateraliyextending bracket 90 1s provided :to wish one end or a spring 91 is secured, the spring!!! acting against a laterally extending :pin 9 1a which has who end securedin and to th'e w'all of the-rotatable sleeve guide 538-. spring Ql isiadapted to'irotate the sleeve and cam follower 83'toirbrling::the material to be tested 11;) against the slower .end

of the penetratoriguard l?! which lservesnsza stop.

The spring 391 and friction .of the engaging :cam

and .tollower surfacescare overcome .by a solenoid 92, control1ed by theaforementioned tilt iSWitCh 81... The solenoid 92 maybe mounted :on the casing wall rlM in the upper chamber 12 and is ,-of the usual welLknown typezhaving a coil:93 and a movable 'core 294. Mounted on the solenoid, .a

. bracket 95 supports-ta lever 56: one :endaof which is ;pivotallysc'onnected to the solenoid core 94. The

other end of the lever 96is1provided with an aperture tmreceive one endof a wire :91 to which is secured .astopror abutment member 88 for abutment with the .lever, the other end of the wire :being secured to the pin-91a of the rotatable cam 'fo'l'lower =83. The wire 91 is enclosed in a flexible-tube 99. I

Ihe control or tilt -switch -8I, Fig. 1, is of the mercury type including a *closed tube 400 con- Y taini-ng a pair of spaced contacts notshown) arranged to be connected or :bridged ,by the mercury upon tilting of the switch or tube in The which is mounted on .the supporting block 43 adjacent the lever member 45. An adjustable abutmentmenrber I03, which may be a screw, is

screwthrea-ded into an arm carried :bythe switch v tube HR) and is arranged .so that its lower end rides on the upper surface of the lever abutment member 50. .Pivotal movement of the switch downwardly or in aclockwise direction is limited --to an upwardly facing seating surface 104 of the bracket 102 and in the down.position of the switch, thecircuit to thesolenoid 92 is open.

Suitable lead wires connect the switch 8] to the solenoid (Bland other lead wires "16 connect the switch to the leadlines 55, T56 of the electric motor -5 4. It will be seen that upon closing the manual-switch 51, the -motor 5'4 starts to operate and that the tiltable switch 8| becomes effective to control the solenoid T92 inaccordance with the operation of the penetrator by the motor.

In the operation of the present machine, on closing of the switch .51, the electricmoto'r'54 rotates the cam '52 which raises and lowers the vertical push rod 51 'torock the'lever Mi-which in turn pivots iever 34 to apply and "remove "the force of weight 40*on the penetrator 24. As previously mentioned, the spring 9 I is adapted to rotate the :cam follower 83 to "raise "the material 18 to be tested against :the lower end of the xpen etivator guard 11:1 and the solenoid 9211s iii tween the engaging cam and :follower' -to return the :Iollo'werand athereiorethe monk support i la to their down positions. When the work "support no is in down position a piece --of anatenial 18 to he tested ispositioned "thereon, as shown and in the down position of the support,

solenoid 92 i's dee-nergized so that 'the spring 9l i is ire'e' to rotate the cam follower. the-di- -"re" tion *to raise the worker part 4-8 toibe tested against the pene'trator guard W. During upward movement-ofathe weight w ,it-heswitoh 84 is close the circu it to the solenoid 82 just prior to the weight reaching its up position.

Uponslight downward movement of the weight 4s, thesoienoid 92 is deenergized'amd the work -*support i laisraised by'the spring rotating the solenoid. *Whenweight 40 lowered the "tubular meniber 2 8 and the penetratorcatrrier arenioved dow-nwarcl,the penetrator projectmg *throu'g' h 'the opening in the lower end ot the the mat'eria-l under test, a back "force-opposed "to guard H and entering or penetrating 'the ma- *terial -or part *"IB undertest. During the initial --=penetra'tion -of the material 1-8, there -'-iS- 'a 'los't- 'nio tion or slipping" between the cooperating -*clutch members 66 and -15! with the result "that *the indicator is not operated-during this -initial penetrating 'movemen-t -'-of the 'penetra-tor which constitutes the application "of -the minor load. However. after a ire-determined penetration -=of the'weigh't H! is built up which results in peri- *pheral contraction of the upper "end portion ot th clutch member 66 which then grips or -"elutches "the wire clutch member 61 to operate the indicator to to register the major load or average hardness of the mate-rial 1-"8. The motor driven cam then moves the "weight upward through *operation of the push rod 5|, 'rocker member and lever 34 to=the inactive position of the weight. which permits the spring I-3 to move the penetrator 24, its holder '23 and the tubular member 28 -=upward=ly. Upon remnvalof ftheinajor load, the upper'end of theaclntch member' BB expandsand releases the wire clutch-'me m- *ber $1, the indicator pointer returning to its -"starting position, It will be seen that during -op'era-t'i6n df the machine, tl-1ecam'5'2 raises and lowers theweigh-t =41) and all that the operator need do is to feed the-parts to loe-tested 'to the machine.

From the toregoing description it will be seen that I have prov-i'ded a -new and improved li'ardness testing machine which is efiicient Landen- "ti-rely automatic in operation. l't'will further :be seen that the present machine, iby reason 1 of the slip clutch which operatively connects the-Boonetrator :and the indicator, that high production "may be obtained with the imachine :since the lm-in'oriload -is automatically applied. In addition, it :will be appreciated that :1 Eli-ave provided a hardness testin machineain which ivariationsi'in :gauge of .a number of parts to bie tested is wornpensate'd -:for automatically.

While :I have shown and described 'in detail: a specific form of 1 my invention it is :to the iu-mierzstood that various changes may he made with- 5011i; departing irommheespiri-t :.or a scope of the .in-

:ven'ti'on whichis-to-be limited ion-1y by :the apadapte'd to'overcomethe spring :and friction ibezpendedclaims.

;What;i,c1aim is: I,

1 In a ,hardnesstesting machine, a supporting, member for the material ,to be tested, a penetrator movable toward and away from said supporting member, said supporting member being movable, toward and away from said penetrator, a lever for movingth penetrator in one direction, a weight member carried by said lever to exert a predetermined force and urge the penetrator into the, materialunder test, said weight member having an inactive position on pivoting of the lever to one position, electrically operated meansto move said supporting member toward and away "from said penetrator, a second lever, said second-named lever loosely abutting said first-named lever, switch means operable by said secondnamed lever and controlling said electrically operated means, a push rod connected to said second-named lever, cam means to reciprocate said push rod, and means operable to actuate said cam means.

,2, In a hardness testin machine, a supporting member for the material to be tested, a reciprocal penetrator movable toward and away irorn said supporting member, a lever operatively connected to said penetrator, a weight membercarried by said lever and on pivoting of the lever in one direction exerting a force to urge said penetrator into the material under test, means to pivot said lever, an expansible-con- ,tractible member acted on by the force of said weight member and carrying said penetrator, said expansible-contractible member having an opening variable in capacity upon expansion and contraction of said member and contractible by the force of said weight member, an indicator for indicating the hardness of the material under .test, means operatively connecting said indicator and said penetrator and extending into said opening, said expansible-contractible member on initial penetration of the material under test contracting to grip said connecting member to actuate said indicator.

3. In a hardness testing machine, a supporting member for material to be tested, a penetrator movable toward and away from said supporting member, means operable to exert a force to urge said penetrator into the material under test, a supporting member for said penetrator and having an expansible-contractible aperture, an, abutment member seating in said secondnamed supporting member and acted against by said force exerting means to actuate said penetrator and contract said aperture, an indicator for indicating the hardness of the ma terial under test, a connecting member for operatively connecting said second-named supporting means and said indicator, said connecting member extending into said aperture for clutching action with said second-named supporting member after initial penetration of the material under test.

4. In a hardness testing machine having penetrator means operable by force exerting means and having indicator means for indicating hard-;

ness of material under test, loss motion connect-- ing means for the penetrator and the force exerting means comprising a movable member operatively connected vto one of the means, a second movable member operatively connected to t the other of the means and cooperable with said first-named member, one of said members having a passage to receive the other of said mem- --bers and contractible upon and in accordance with the application of a predetermined force;

acting to urge thepenetratcrmeans into material under test to ,operatively connect the penetrator means and the indicator means.

5. In a hardness testing machine, a supporting member for. material to be tested, a movable penetrator member for penetrating the material, one of said members having an initial movement towardv the other of said members dependent upon the thickness of the material and prior to penetration of the material to obtain desired relative positions of saidpenetrator member and the material, electrically operated means operable to move said one member toward and away from said other. member, means operable to mov the penetrator member to penetrate the test material, lever means operatively connecting said last-named means. and said penetrator member, and .switch means actuated by said lever means and controlling said electrically operated means. I

6.111 a hardness testing machine, a supporting member for material to be tested, a movable penetrator member, means to exert a force operable to move said penetrator to penetrate the material, one of said members being movable toward the other of said members depending upon the thickness of the material and prior to penetration thereof by the penetrator, means to exert a force operable to move said penetrator to penetrate the material, cam means operable to movesaid one member toward and away from the other member,ispring means to operate said cam means to move said one member in one direction, electrically operated means operable to overcome said spring meansand friction of said-cam means to move said one member in the opposite direction, switch means controlling penetrator being movable upon application of said force exerting means relative to said guard to" project through said opening to penetrate thematerial, one of said members being initially movable toward the other of said members prior to effective application of said force exerting means so that the material will be in contact with said guard, means operable automatically to move said one member toward the other member, and control means operable in accordance with application of said force exerting means to control said last-named moving means.

8. In a hardness testing machine, a movable penetrator for material to be tested, a supportportingmember, stop means tolimit movement of said supporting member toward said penetrator, spring means operable to actuate said cam means to move said supporting member to said stop means prior to effective application of the weight, electrically operated means operable to actuate'said cam means to move said supporting member away from said penetrator after application of the weight and also to tension said spring means, and switch means actuated by and in accordance with movement of said weight member and operable to control said electrically operated means.

9. In a hardness testing machine, a work abutment and a penetrator member one movable toward the other, the movable member including a plurality of hollow sections and a collet intermediate said sections, means for applying a predetermined force to one of said sections to 

